[Feature Request] Allow Bulk/Mass Create of ICMP Monitors

[Erikg346]

Describe the feature:

Prior, in Heartbeat, we could add/remove/update a monitor that would allow multiple instances of hosts/IPs.

Currently, you have to create a single ICMP monitor for each host/IP. This is very tedious as I have over 300+ hosts I want to ping.
Allow there to be the ability to add a list of hosts or the ability to create multiple monitors using API.

Describe a specific use case for the feature:
Our team wants to monitor our network by pinging host endpoints. Currently, we have to build a monitor for each endpoint. We have used network discovery tools before and it would be a great addition if we had something like that before elastic/beats#38145. But for now, it would be helpful for a easier way to mass create monitors.

[vigneshshanmugam]

Tying in with #627

[vigneshshanmugam]

@Erikg346 Would supporting Anchors for the time being help #888 ?

[MakoWish]

I would also like to see this. The YAML files for Heartbeat could even be created programmatically, so manually adding monitors one at a time with the GUI for Synthetics is painfully tedious.

[vigneshshanmugam]

I have a PR #903 for the Anchor support, will be released in the next few days. Thank you.